Surface defects and instanton-vortex interaction

A. Gorsky, B. Le Floch, A. Milekhin +1

We propose a simple formula for the 4d-2d partition function of half-BPS surface defects in $d=4,\mathcal{N}=2$ gauge theories: $Z^{\text{4d-2d}}=\langle Z^{\text{2d}} \rangle_{\…